PAIN CONTROL IN PALLIATIVE CARE

• Pain is common in patients with life-limiting illness
• Physical, psychological, social and spiritual factors can influence the experience of pain
• Pain can be well controlled in the majority of patients 

Types of pain

• Visceral/soft tissue pain
• likely to be opioid sensitive
• Bone pain
• often partially opioid sensitive
• may respond to NSAIDs, radiotherapy and bisphosphonates
• Nerve pain
• partially opioid sensitive
• may respond well to adjuvant analgesics

Pain assessment

• Take a pain history using SOCRATES
• S – Site
• O – Onset
• C – Character
• R – Radiation
• A – Associated symptoms
• T – Timing
• E – Exacerbating and relieving factors
• S – Severity
• Use a pain scale
• 0–10
• visual analogue scale
• Analgesic history
• current analgesia
• previously tried analgesia
• effectiveness of treatment
• side effects of treatment

Principles

• Identify and treat cause of pain if possible
• Select treatment appropriate for the pain and patient’s needs
• Keep it simple and use oral medication whenever possible
• Pain relief should be by the mouth (oral), by the clock (regular) and by the WHO analgesic ladder
• add adjuvant analgesics (e.g. NSAID/anticonvulsant/antidepressant/antispasmodic) with any step

Step 1 – non-opioid

Paracetamol

• Analgesic and antipyretic
• Dose: 500 mg–1 g 4–6 hrly (maximum dose 4 g in 24 hr)

Non-steroidal anti-inflammatories – NSAIDs

• Anti-inflammatory, anti-pyretic and analgesic
• 1^st line NSAID – ibuprofen
• 1.2–2.4 g daily in 3–4 divided doses

Caution

• See BNF for cautions and contraindications before starting NSAID
• History of gastroduodenal ulceration – prescribe gastroprotective drug (e.g. PPI)
• Concomitant corticosteroids or anticoagulant – prescribe gastroprotective drug (e.g. PPI)

Step 2 – weak opioid

• Useful for moderate pain
• Seldom useful to change from one preparation to another
• If regular doses do not provide adequate analgesia, move up WHO analgesic ladder to Step 3
• Prescribe regular laxative to prevent constipation

Drugs

• Codeine 30–60 mg 4-hrly (maximum dose 240 mg in 24 hr)
• Co-codamol available as:
• 8/500 (codeine 8 mg with paracetamol 500 mg)
• 30/500 (codeine 30 mg with paracetamol 500 mg)
• dose: 2 tablets 4–6 hrly (maximum 8 in 24 hr)

Step 3 – strong opioid

• If regular weak opioid not controlling pain, initiate modified release morphine (e.g. Zomorph^®, MST^®)
• usual starting dose 10–15 mg oral 12-hrly
• remember 60 mg codeine 6-hrly is equivalent to 24 mg oral morphine in 24 hr
• Also prescribe as required immediate release morphine (e.g. morphine sulphate solution) for breakthrough pain
• prescribe one-sixth of the total daily dose of regular morphine (usually 2.5–5 mg)

Communication

• Ask about and discuss any concerns and misconceptions about starting strong opioids
• Provide verbal and written information on the use of strong opioids
• how to take them
• side effects
• safe storage
• how pain will be reviewed and who to contact if any problems
• If patient wishes to continue to drive, give verbal and written advice on the law on driving when taking opioid medications

Review and titration

• Nursing assessment of pain at least 4-hrly (e.g. drug rounds, observations)
• Medical review of pain control 24–48 hr after starting regular strong opioids 

Patient still experiencing pain and pain is opioid sensitive

• Consider increasing regular dose
• add up total amount of morphine given in last 24 hr including modified release and immediate release morphine. Divide by 2 and prescribe 12-hrly (rounded to the nearest 5 mg)
• ensure dose of as-required immediate release morphine is adjusted when the dose of modified release morphine changed. It should be one sixth of the total daily dose of regular morphine
• see Example

Side effects

• Constipation can occur with all opioids
• prescribe regular laxatives when prescribing regular strong opioids
• it may be necessary to increase the dose of laxatives as the dose of morphine increases
• Nausea may occur when strong opioids started or dose increased but this is likely to be transient
• if nausea develops, use regular haloperidol 1.5 mg oral or SC at night
• consider stopping after 5 days
• Drowsiness or impaired concentration may occur when strong opioids started or at dose increase. If persistent or severe:
• if pain controlled, reduce dose
• if pain not controlled, consider switching to alternative opioid. See Alternative opioids below
• if side effects persist or considering alternative opioids, refer to hospital palliative care team

Alternative opioids

• May be used to improve side effect profile
• Oxycodone is the preferred second line opioid
• Do not use fentanyl patches to manage uncontrolled pain due to long half-life
• See Opioid equivalence tables
• use dose in equivalence table as an approximate guide
• If considering alternative opioid preparations, seek advice from hospital palliative care team

Opioids by continuous subcutaneous infusion

• Unless there is a problem with absorption or administration, opioids via continuous subcutaneous infusion will not provide better analgesia than oral route
• See Continuous subcutaneous infusion (CSCI) in palliative care guideline